The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Vehicles typically include a powertrain system that generates drive torque and transfers the drive torque to driven wheels, which propel the vehicle along a surface. Powertrain systems come in various configurations and include various components. A traditional powertrain system includes a torque source, such as an internal combustion engine (ICE), a transmission that is coupled to the torque source and a driveline that is coupled to an output of the transmission. The driveline can be a front-wheel driveline (FWD), a rear-wheel driveline (RWD) or a four-wheel driveline (4WD), which typically also includes a transfer case. Some powertrain systems include multiple torque sources, such as is the case with a hybrid electric powertrain system, which includes an ICE and an electric motor/generator.
Powertrain systems also include several torque features, each of which seeks to influence the amount of drive torque at various points along the powertrain system. An upper level or global torque feature is a vehicle driver, who commands a desired output torque from the torque source(s) or a desired axle torque based on a driver input. Exemplary driver inputs include, but are not limited to, an accelerator pedal and a cruise control system. Modern powertrain systems include additional torque features such as vehicle stability control systems, traction control systems, engine overspeed protection systems, transmission shift quality systems, engine and/or transmission component protection systems and/or driveline component protection systems, among several others. The torque features can number in the tens to over a hundred, depending upon the particular configuration of the powertrain system.
The torque features of a particular powertrain system are independent and can often seek to control the drive torque at the same time. Because the powertrain system can only produce a single drive torque value at any time, an arbitration system is required to determine the correct drive torque to produce. Traditional powertrain systems are overly complex and seek to establish a hierarchy of desired torque behavior. Such traditional powertrain systems use one or two primary design methods. They either assign various priority levels to a torque request to enable arbitration based on priority or they rely on complex pre-defined interactions. Both of these methods result in complex systems and system behavior compromises.